The present invention is generally relates to household appliances, and more particularly to coffee makers.
Brewing coffee, also called a dripped coffee method, is the most common home coffee making method. To produce brewed coffee, hot, but not boiling, water drips through coffee grinds and the hot water extracts coffee particles from the grinds to form coffee. The coffee often drips into a coffee pot or a thermal carafe.
Many people use automatic drip coffee (ADC) makers to brew coffee. A typical design of an automatic drip coffee maker includes a water reservoir and a coffee brew basket. Water is poured into the reservoir and a user starts the brewing cycle, by either pressing an xe2x80x9conxe2x80x9d button or setting the time for the brewing cycle and that time elapsing. Upon starting of the brewing cycle, waters flows from the reservoir through a heater of some kind, usually a heater tube. The heated water is routed to above the brew basket, and is allowed to drip through the brew basket, through the coffee grinds, and into a coffee pot or thermal carafe.
Although conventional automatic drip coffee makers work well for their intended purpose, one problem with their associated use is that not all coffee grinds in the brew basket are contacted with the hot water during the brewing process. Thus, the coffee grinds in the brew basket are not extracted evenly. Instead, often a cradle is formed in the coffee grinds directly below where the water drips into the brew basket. The cradle is created by the pressure exerted by the heated water. This pressure comes from two sources: the pressure generated by the steam in the water tube and the weight of the water being pulled down by gravity into the brewing basket.
Formation of the cradle in the coffee grinds causes the grinds in the cradle to be overexposed to the hot water, which leads to overextraction, or overcooking, of those grinds. This overextraction makes the grinds smaller in size which increases the size of the cradle and creates an easier path for the flow of water out of the brew basket. Thus, the cradle problem compounds after a cradle is starded. As a result, typically, after a period of initial brewing, water has a tendency to flow directly through the cradle without much extraction of the coffee grinds taking place.
One prior art method of minimizing the cradle effect is to use a vertical spray shower head in which water drips from a number of different locations that are spread over the brewing basket. Although this system works well to spread the hot water over the coffee grinds, often numerous cradles are formed at each spray location, resulting in overextraction at each spray location. Moreover, the vertical spray shower heads often cause pressure backflow to the heating system for a coffee maker, making the heating components, such as a thermostat, cycle often to maintain appropriate pressure in the coffee maker.
The present invention provides a drip coffee maker having a horizontal spray of heated water into a brew basket. To this end, in accordance with one embodiment of the present invention, the drip coffee maker includes a horizontal spray shower head that delivers water primarily in horizontal directions. The horizontal spray shower head is configured and arranged such that the horizontal spray of water lightly lands upon the grinds and is thoroughly spread over the grinds. Thus, the spray from the shower head does not move the coffee grinds to one side or the other in a brew basket. In addition, because the heated water travels to the brew basket in a horizontal direction, much of the effect of gravity is removed and the amount the heated water is spread may be increased.
The horizontal spray shower head may be used to expose the top layer of coffee grinds in the brew basket to an equal amount of hot water within a few seconds of brewing start time. The heated is continually added uniformly over the coffee grinds, and the water filters down evenly through the coffee grinds in the brew basket. By immersing the top layer of coffee grinds uniformly with the hot water, the coffee grinds at each location in the brew basket are all subjected to the same water pressure. In this manner, the horizontal spray shower head effectively eliminates the problem of a cradle being formed in the brew basket. In addition, the maximum number of coffee grinds within the brew basket are given exposure to the heated water. This exposure allows more coffee to be extracted from fewer grinds, thus conserving coffee and avoiding overcooking of the grinds.
In accordance with another aspect of the present invention, the horizontal spray shower head is configured such that water may flow freely through the shower head without backflow pressure. Without the backflow pressure, the heating components for the coffee maker do not have to work as hard to produce an optimal flow rate of heated water. Thus, a coffee maker utilizing the horizontal spray shower head is more efficient. Moreover, without backflow pressure, the flow rate is directly related to the heat output of heater for the coffee maker, and thus may be more effectively controlled. This feature permits a manufacturer to set the flow rate of the coffee maker with certainty by simply selecting the appropriate wattage for a heater.
Other advantages will become apparent from the following detailed description when taken in conjunction with the drawings, in which: